1. The Field of the Invention
The present invention relates to apparatus and methods for sealing an iatrogenic puncture in a vessel or other body lumen formed in conjunction with a diagnostic or therapeutic treatment. More particularly, the present invention provides apparatus comprising an introducer sheath including a puncture site closure device comprising an expandable clip with elastic memory. Also, the present invention provides apparatus comprising an introducer sheath including a puncture site closure device comprising a bioabsorbable clip. Further, the present invention includes an apparatus and methods for positioning such a device relative to the body lumen before delivery
2. The Relevant Technology
Catheterization and interventional procedures, such as angioplasty and stenting, generally are performed by inserting a hollow needle through a patient's skin and muscle tissue into the vascular system. A guide wire then is passed through the needle lumen into the patient's blood vessel. The needle is removed and an introducer sheath is advanced over the guide wire into the vessel. A catheter typically is passed through the lumen of the introducer sheath and advanced over the guide wire into position for a medical procedure. The introducer sheath therefore facilitates insertion of various devices into the vessel while minimizing trauma to the vessel wall and minimizing blood loss during a procedure.
Upon completion of the medical procedure, the catheter and introducer sheath are removed, leaving a puncture site in the vessel. Commonly, external pressure is applied until clotting and wound sealing occurs. However, this procedure is time consuming and expensive, requiring as much as an hour of a physician's or nurser's time, is uncomfortable for the patient, and requires that the patient be immobilized in the operating room, cathlab, or holding area. Furthermore, a risk of hematoma exists from bleeding prior to hemostasis.
Various apparatus have been developed for percutaneously sealing a vascular puncture by occluding or suturing the puncture site. For example, U.S. Pat. Nos. 5,192,302 and 5,222,974 to Kensey et al., describe the use of a biodegradable plug delivered through the introducer sheath into the puncture site. When deployed, the plug seals the vessel and provides hemostasis. Such devices have been slow to gain acceptance in the medical community, however, due to difficulties encountered in positioning the plug within the vessel. Moreover, the agents used to occlude the puncture site are animal-derived, typically collagen-based. Thus, a risk of adverse immunoresponse exists.
Another previously known technique comprises percutaneously suturing the puncture site with specialized apparatus. Such apparatus is described, for example, in U.S. Pat. No. 5,304,184 to Hathaway et al. While percutaneous suturing devices may be effective, a significant degree of skill may be required on the part of the practitioner. Because such devices are mechanically complex, they tend to be relatively expensive to manufacture.
Surgical staples and resilient clips for external skin wound closure are well known in the art, Examples include U.S. Pat. No. 5,026,390 to Brown and U.S. Pat. No. 5,683,405 to Yacoubian et al, which both describe resiliently deformable closure devices suitable for manual external application.
To reduce the cost and complexity of percutaneous puncture closure devices, such devices employing resilient clips or staples have been developed. U.S. Pat. No. 5,478,354 to Tovey et al. describes the use of resilient clips in conjunction with a trocar to close abdominal puncture wounds. U.S. Pat. No. 5,810,846 to Vimich et al. describes a specialized apparatus for closing a vascular puncture site with a plastically deformable clip. The apparatus preferably is advanced over a guide wire through a cannula to the surface of the puncture site, where the staple-like clips are delivered to close the wound.
U.S. Pat. No. 5,782,861 to Cragg et al. describes specialized apparatus for closing a puncture site with a detachable clip. The apparatus comprises a hollow shaft, having a distal end formed with one or more opposed pairs of resilient grasping prongs, that is advanced over a guide wire through a coaxial hollow tube to a position at the distal end of the tube just proximal of the puncture. The grasping prongs are extended beyond the distal end of the tube to grasp the vessel on opposing sides of the puncture. The shaft then is partially retracted, causing the prongs to contract within the tube, thereby sealing the puncture site. Both of the devices described in the foregoing patents have the drawback that a separate device must be deployed through the introducer sheath to close the puncture site, thus prolonging the procedure. Moreover, both devices require relatively complex apparatus and involve time consuming manipulation to achieve hemostasis.
The use of back bleed indication as a positioning technique within a vascular puncture is known. For example, U.S. Pat. No. 4,317,445 to Robinson describes a flashback chamber for providing visual indication of venous entry of a cannula. However, that device does not discuss vascular wound closure. U.S. Pat. No. 5,676,689 to Kensey et al., which claims priority from the U.S. Pat. No. 5,222,974 discussed above, uses a vessel location device to simplify positioning of the biodegradable plug. The vessel locator enables blood from the vessel to flow there through so that the position of the vessel may be determined. However, the Kensey system only proffers one closure device, and that device is complex and raises concerns about biocompatibility. It also requires the closure component to be positioned within the puncture, thereby increasing the likelihood of dangerous over-advancement of the plug into the vessel.
The percutaneous puncture closure devices described in the foregoing patents generally have the drawback that they require relatively complex mechanisms and require time consuming manipulation to achieve hemostasis. It therefore would be desirable to provide apparatus and methods suitable for vascular puncture closure that overcome these disadvantages of previously known devices. It also would be desirable to provide apparatus and methods for vascular puncture closure that quickly and effectively achieve hemostasis. It further would be desirable to provide vascular puncture closure apparatus and methods that do not require the introduction of additional apparatus at the completion of the catheterization procedure to achieve closure. It still further would be desirable to provide apparatus and methods suitable for vascular puncture closure that do not introduce animal-derived material into the bloodstream. It still further would be desirable to provide apparatus and methods wherein all foreign materials left in a patient's body are bioabsorbable.